Modular mass storage system and method therefor

ABSTRACT

A modular mass storage system and method that enables cableless mounting of ATA and/or similar high speed interface-based mass storage devices in a computer system. The system includes a printed circuit board, a system expansion slot interface on the printed circuit board and comprising power and data pins, a host bus controller on the printed circuit board and electrically connected to the system expansion slot interface, docking connectors connected with the host bus controller to receive power and exchange data therewith and adapted to electrically couple with industry-standard non-volatile memory devices without cabling therebetween, and features on the printed circuit board for securing the memory devices thereto once coupled to the docking connectors.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a division patent application of co-pending U.S. patentapplication Ser. No. 12/713,349, filed Feb. 26, 2012, and claims thebenefit of U.S. Provisional Application No. 61/162,488, filed Mar. 23,2009, the contents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

The present invention generally relates to computer memory systems, andmore particularly to a modular mass storage system that enables storagedevices to be installed and removed from a computer without the use ofcables through which the storage devices receive power and exchange datawith the motherboard of a computer system.

Current data (mass) storage devices in personal computers (PCs) andservers typically use rotatable media-based hard disk drives (HDDs)featuring one or more magnetic platters as the data carrier and aread/write head positioned over the relevant sector by means of anactuator. In recent years, the trend has been to miniaturize these HDDssuch that currently the largest form factor is the 3.5-inch drive. The3.5-inch HDDs are still the predominant non-volatile storage device indesktop computers, where they are typically mounted in drive bays. Inthe notebook sector, the more common HDD is the 2.5-inch drives in aslim form factor mounted in a specialized compartment in the notebookchassis.

Aside from physical dimensions, the weight of an HDD plays an importantfactor with respect to the mounting of an HDD in a computer, sincecertain prerequisites must be met for the mounting fixture. Moreoverthere are also some orientational factors that must be taken intoconsideration, for example, drives mounted at an angle appear to havehigher wear on their bearings than do drives oriented so that theirspindle axes are vertical during normal operation of the computer.Finally and significantly, the mass of the actuator is often sufficientto cause some degree of movement of the entire drive. Primarily becauseof these weight and stability concerns, HDDs are often mounted inspecialized drive bays within the chassis, often with the use of rubbergrommets to dampen vibrations and shock between the HDDs and thechassis. Power and data connections are made through cables to themotherboard or any add-on host-bus controller, as well as the powersupply unit (PSU) of the computer.

The introduction of solid state drives (SSDs) into the computer markethas lessened and in some cases eliminated some of the above-notedconcerns associated with HDDs. SSDs are slimmer, lighter and lack movingparts, and therefore their operation is intrinsically vibration-free andthey have almost unlimited shock resistance. Likewise, SSDs are notsensitive to orientation whatsoever. As such, SSDs allow for a widespectrum of mounting methods for computer systems.

Redundant arrays of independent disks (RAID), which encompass computerdata storage schemes that divide and replicate data among multiple HDDs,utilize a dedicated controller, such as an ISA (industry standardarchitecture) bus or a PCI (peripheral component interconnect) or PCIexpress (PCIe) expansion card. Since the introduction of Serial ATA(advanced technology attachment), or SATA, several chipset manufacturershave added RAID functionality to their I/O controllers and Southbridges(also known as I/O controller hub (ICH) or a platform controller hub(PCH)). These RAID controllers provide a software-based RAID logic,which is sufficient for RAID Levels 0 and 1 (striping and mirroring,respectively) or a software-based RAID Level 5 configuration withdistributed parity in which the central processing unit (CPU) handlesthe parity calculations. In either case, several HBA (host bus adapter)interfaces or channels are using a unified upstream signal path to thesystem memory for direct memory access (DMA), in which the HBA acts asbus master to initiate the data transfers.

In another approach, Fusion-io recently introduced a PCIe-based RAIDcard with onboard, fully-integrated multiple arrays of NAND chips.Advantages of this approach are that the PCIe interface provides a largeamount of bandwidth to the system logic, and the NAND chips are notinterfaced through additional cabling and logic but instead areaddressed directly through an integrated controller on the card. Despiteits technical elegance, there are certain concerns regarding thistechnology in its current form. Regarding its implementation, becausethe device is fully integrated instead of modular, any component failurewill render the entire device inoperable. From a consumer viewpoint,because the device is at present a single-source solution, any majoracceptance in the market is handicapped by a supply monopoly, andpricing may be prohibitive for wide distribution.

In view of the above, it would be desirable if further solutions wereavailable that are capable of combining the possibilities of newgenerations of drives with a modular design in which off-the-shelfcomponents can be used in any combination desired by the owner,providing a level of expandability, flexibility and serviceability atthe lowest total cost of ownership.

BRIEF DESCRIPTION OF THE INVENTION

The present invention provides a modular mass storage system and methodthat enables cableless mounting of ATA and/or similar high speedinterface-based mass storage devices in a computer system.

According to a first aspect of the invention, the modular mass storagesystem includes a printed circuit board, a system expansion slotinterface on the printed circuit board and comprising power and datapins, a host bus controller on the printed circuit board andelectrically connected to the system expansion slot interface, dockingconnectors connected with the host bus controller to receive power andexchange data therewith and adapted to electrically couple withindustry-standard non-volatile memory devices without cablingtherebetween, and means on the printed circuit board for securing thememory devices thereto once coupled to the docking connectors.

According to a second aspect of the invention, the method involvesinstalling a mass storage system on a computer system. The mass storagesystem comprises a printed circuit board, a system expansion slotinterface on the printed circuit board and comprising power and datapins, a host bus controller on the printed circuit board andelectrically connected to the system expansion slot interface, dockingconnectors connected with the host bus controller to receive power andexchange data therewith and adapted to electrically couple withindustry-standard non-volatile memory devices without cablingtherebetween. Industry-standard non-volatile memory devices are theninstalled in the mass storage system by removably coupling the memorydevices to the docking connectors and removably securing the memorydevices to the printed circuit board.

In view of the above, it can be seen that the invention features meansfor mechanically and electrically integrating compliant mass storagedevices as daughter devices or modules on a parent expansion card. Atechnical effect of this invention is the elimination of cabling as aresult of direct mounting of individual drives on a RAID adapter. Theinvention promotes a compact design of an entire mass storage device, aswell as a modular design capable of using off-the-shelf drives to allowfor customized configuration. As a result, in the event of a failure ofany individual device, the failed device can be replaced inexpensivelywithout losing the entire mass storage device. If redundancy is used, anentire array of mass storage devices can be rebuilt on the fly withoutdata loss. Furthermore, a direct PCl/PCIe interface can be used to allowfor high data transfer rates. From an economics standpoint, anadditional advantage is the ability to use multiple vendor standarddevices, eliminating concerns associated with single-source solutionssuch as the Fusion-io card.

Other aspects and advantages of this invention will be betterappreciated from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic overview of a modular mass storage system forcomputer systems according to an embodiment of the present invention,wherein the system is configured as a host bus adapted that includesmultiple mass storage devices (drives) removable engaged with dockingconnectors.

FIG. 2 is a perspective view of the modular mass storage system of FIG.1, with one of the drives removed to illustrate the mounting andinterface to the drives.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a compact, fully-integrated, modular massstorage system 10 for computer systems. In the embodiment depicted inFIGS. 1 and 2, the mass storage system 10 is generally configured as ahost bus adapter (HBA) comprising an expansion card 12, represented inFIGS. 1 and 2 as a PCI express (PCIe) expansion card, on which an arrayof data (mass) storage devices 14 associated with the host bus adapterare individually removably mounted. The electronics of the host busadapter serve to connect the storage devices 14 to a computer (notshown) or other host system. The storage devices 14 may be ATA and/orsimilar high speed interface-based mass storage devices havingcommonly-utilized mass memory drive configurations, including but notlimited to IDE (integrated drive electronics) mode, advanced hostcomputer interface (MCI), and RAID Levels 0, 1, 10 and 5.

The expansion card 12 in FIGS. 1 and 2 comprises a printed circuit board16 on which are the electronics of the host bus adapter are mounted,which in FIG. 1 includes a RAID controller 18 along with auxiliaryelectronics such as a data cache 20 of integrated circuit memory devicessuch as SDRAM (synchronous dynamic random access memory), SRAM (staticrandom access memory) or pipeline burst SRAM chips for data buffering,and a voltage regulator module represented as including a MOSFET 22 andcapacitors 24. In the case of RAID Level 5, parity calculations can becarried out in software using the central processor on the computersystem motherboard (not shown) or a dedicated parity processor (notshown) on the card 12. The card 12 is further represented as comprisingmechanical retention brackets 26 that secure the mass storage devices14, represented in FIG. 1 by four SSDs and/or HDDs drives. The storagedevices 14 have male connectors (not shown) by which they are directlyplugged into female docking connectors 28 on the card 12. The connectors28 preferably provide both power and data connections for the storagedevices 14, similar to SATA drives. The data cache 20 is used to bufferwrites and/or prefetch reads from the array of storage devices 14. Asystem expansion slot interface 30 in the form of a PCIe edge connectorprovides an interface with an expansion slot of the motherboard forsupplying power to the card 12 and exchanging data between the card 12and motherboard. An auxiliary power connector 32 is also shown by whichadditional power can be supplied to the card 12, if so desired.Electrical connections (not shown) on the card 12 can be achieved inaccordance with conventional industry practices.

FIG. 2 represents a perspective view of the system 10 of FIG. 1, withone of the storage devices 14 removed to illustrate the mounting andinterface of the storage devices 14 with the docking connectors 28 andretention brackets 26. As evident from FIG. 2, both sides of the card 12can carry storage devices 14, as well as their connectors 28. Theretention brackets 26 provide the mechanical stability required for thestorage devices 14 on the card 12, and serve as mechanical fixtures thathelp to align each individual device 14 as it is inserted into itsdocking connector 28. As such, the brackets 26 are preferably somewhatpliable and configured to allow the storage devices 14 to slide betweendistal arms 26A (FIG. 2) of the brackets 26 in a direction parallel tothe surface of the printed circuit board 16 while applying sufficientforce normal to the board surface to secure the storage devices 14against the board surface.

The number of docking connectors 28 can vary, depending on the length ofthe card 12. In the embodiment of FIGS. 1 and 2, four docking connectors28 are shown though it should be understood that any number ofconnectors 28 could be provided, including a single connector. Becauseof the bandwidth requirements of the card 12 and its storage devices 14,the expansion slot interface 30 will typically use eight lanes forsignaling, though a single lane, four lanes or sixteen lanes are alsopossible.

As evident from FIGS. 1 and 2, the docking connectors 28 and expansionslot interface 30 provide for cableless mounting and interfacing of themultiple mass storage devices 14. Because it is advantageous to keep theamount of external cabling at a minimum, the power connections of theexpansion slot interface 30 preferably use the full length of theinterface 30, even if the data connections only use a fraction of thelanes available. The optional auxiliary power connector 32 on the card12 can be used to supply auxiliary power from the system's motherboardto the card 12 independent of power supplied to the card 12 by theinterface 30.

In view of the above, it can be seen that the mass storage system 10 canbe installed on a motherboard of a computer before and after installingand securing the storage devices 14 on the card 12. It can also be seenthat one or more of the storage devices 14 can be removed from the massstorage system 10 by simply uncoupling the device 14 from itscorresponding docking connector 28.

It should be understood that other types of mass storage devices couldbe used in place of the ATA storage devices 14 identified in referenceto the embodiment of FIGS. 1 and 2, For example, USB (Universal SerialBus) flash (thumb) drives may be mounted in one or more of the dockingconnectors 28 of the expansion card 12 in a manner similar to what isshown in FIGS. 1 and 2 and described above. This configuration maybecome more attractive with the emergence of the USB Revision 3.0“Superspeed” standard (USB 3.0). Other types of devices or protocols arealso possible, nonlimiting examples of which include HDMI(high-definition multimedia interface), IEEE 1394 interface (e.g.,Apple's FIREWIRE), and SO-DIMMs (small outline dual in-line memorymodules) using non-volatile memory components are also within the scopeof this invention.

While the invention has been described in terms of a specificembodiment, it is apparent that other forms could be adopted by oneskilled in the art. For example, the physical configuration of the card10 and its components could differ from that shown. Therefore, the scopeof the invention is to be limited only by the following claims.

The invention claimed is:
 1. A method of installing a mass storagesystem on a computer system, method comprising: providing a mass storagesystem comprising a printed circuit board, a system expansion slotinterface on the printed circuit board and comprising power and datapins, a host bus controller on the printed circuit board andelectrically connected to the system expansion slot interface, dockingconnectors connected with the host bus controller to receive power andexchange data therewith and adapted to electrically couple withindustry-standard non-volatile memory devices without cablingtherebetween; and installing at least one industry-standard non-volatilememory device in the mass storage system by removably coupling thememory device to one of the docking connectors and removably securingthe memory device to the printed circuit board.
 2. The method accordingto claim 1, further comprising installing the mass storage system on amotherboard of a computer prior to installing the memory device on themass storage system.
 3. The method according to claim 1, furthercomprising removing the memory device from the mass storage system byuncoupling the memory device from its corresponding docking connector.4. The method according to claim 1, wherein the system expansion slotinterface is a PCIe connector.
 5. The method according to claim 4,wherein the power and data pins conform to female SATA connectors, eSATAconnectors, USB connectors, HDMI connectors, IEEE 1394 interfaceconnectors or SO-DIMM sockets.
 6. The method according to claim 1,wherein the host bus controller is configured as a RAID controller. 7.The method according to claim 6, wherein the host bus controllercomprises onboard SDRAM, SRAM or pipeline burst SRAM used as data cache.8. The method according to claim 6, wherein the host bus controllercomprises onboard logic capable of carrying out parity calculations forthe RAID controller.
 9. The method according to claim 1, wherein thememory device is one of a plurality of memory devices installed in themass storage system by removably coupling the memory devices to aplurality of the docking connectors and removably securing the memorydevices to the printed circuit board.
 10. The method according to claim9, wherein the memory devices comprise at least two drives chosen fromthe group consisting of solid state drives, hard disk drives, USB 3.0flash drives, SO-DIMMs, HDMI drives, and IEEE 1394 interface drives. 11.The method according to claim 9, wherein the memory devices comprise atleast one USB 3.0 flash drive.
 12. The method according to claim 9,wherein the memory devices comprise at least one SO-DIMM.